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Masonry is the building of structures from individual units, which are often laid in and bound together by
mortar Mortar may refer to: * Mortar (weapon), an indirect-fire infantry weapon * Mortar (masonry), a material used to fill the gaps between blocks and bind them together * Mortar and pestle, a tool pair used to crush or grind * Mortar, Bihar, a village in ...
; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are
brick A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...

brick
, building
stone A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition and the way in which it is formed. Rocks form the Earth's outer solid layer, th ...
such as
marble Marble is a metamorphic rock , a type of metamorphic rock Metamorphic rocks arise from the transformation of existing rock (geology), rock to new types of rock, in a process called metamorphism upright=1.35, Schematic representation of ...

marble
,
granite Granite () is a coarse-grained (phaneritic A phanerite is an igneous rock Igneous rock (derived from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Lat ...

granite
, and
limestone Limestone is a common type of carbonate In chemistry, a carbonate is a salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of Salt (chemistry), salts; salt in its na ...

limestone
,
cast stone Cast stone or reconstructed stone is a highly refined architectural precast concrete File:Precastbuilding.jpg, Interior view of the walls, supports, and roof of a precast commercial shop. Utilities are preassembled into the precast components ...
,
concrete block A concrete masonry unit (CMU) is a standard-size rectangular block used in building construction Construction is a general term meaning the art and science Science (from the Latin word ''scientia'', meaning "knowledge") is a syste ...

concrete block
,
glass Glass is a non- crystalline, often transparency and translucency, transparent amorphous solid, that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by ...

glass
block, and
adobe Adobe (; ) is a building material Building material is material used for construction Construction is a general term meaning the art and science to form Physical object, objects, systems, or organizations,"Construction" def. 1.a. ...

adobe
. Masonry is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern in which the units are assembled can substantially affect the durability of the overall masonry construction. A person who constructs masonry is called a mason or
bricklayer A bricklayer, which is related to but different from a mason, is a Artisan, craftsman and tradesman who lays bricks to construct brickwork. The terms also refer to personnel who use Cinder block, blocks to construct blockwork walls and other f ...

bricklayer
. These are both classified as construction trades.


Applications

Masonry is commonly used for walls and buildings. Brick and concrete block are the most common types of masonry in use in industrialized nations and may be either load-bearing or non-load-bearing. Concrete blocks, especially those with hollow cores, offer various possibilities in masonry construction. They generally provide great compressive strength and are best suited to structures with light transverse loading when the cores remain unfilled. Filling some or all of the cores with concrete or concrete with steel reinforcement (typically
rebar Rebar (short for reinforcing bar), known when massed as reinforcing steel or reinforcement steel, is a steel bar or mesh of steel wires used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the con ...
) offers much greater tensile and lateral strength to structures. Masonry workers are typically paid hourly depending on their position.


Advantages

* The use of materials such as bricks and stones can increase the thermal mass of a building. * Masonry is a non-combustible product and can protect the building from fire. * Masonry walls are more resistant to projectiles, such as debris from hurricanes or tornadoes.


Disadvantages

* Extreme weather, under certain circumstances, can cause degradation of masonry due to expansion and contraction forces associated with freeze-thaw cycles. * Masonry tends to be heavy and must be built upon a strong foundation, such as reinforced concrete, to avoid settling and cracking. * Other than concrete, masonry construction does not lend itself well to mechanization, and requires more skilled labor than stick-framing. * Masonry consists of loose components and has a low tolerance to oscillation as compared to other materials such as reinforced concrete, plastics, wood, or metals.


Structural limitations

Masonry has high compressive strength under vertical loads but has a low tensile strength (against twisting or stretching) unless reinforced. The tensile strength of masonry walls can be increased by thickening the wall, or by building masonry ''piers'' (vertical columns or ribs) at intervals. Where practical, steel reinforcements such as
windpostA windpost is a structural A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to fo ...
s can be added.


Veneer masonry

A masonry veneer wall consists of masonry units, usually clay-based bricks, installed on one or both sides of a structurally independent wall usually constructed of wood or masonry. In this context, the brick masonry is primarily decorative, not structural. The brick veneer is generally connected to the structural wall by brick ties (metal strips that are attached to the structural wall, as well as the mortar joints of the brick veneer). There is typically an air gap between the brick veneer and the structural wall. As clay-based brick is usually not completely waterproof, the structural wall will often have a water-resistant surface (usually
tar paper Tar paper is a heavy-duty paper used in construction. Tar paper is made by impregnating paper or fiberglass mat with tar, producing a waterproof material useful for roof construction. Tar paper is distinguished from roofing felt which is impregnat ...
) and
weep hole A weep, a weep hole, or a weep-brick is a small opening that allows water to drain from within an assembly. Weeps are located at the bottom of the object to allow for drainage; the weep hole must be sized adequately to overcome surface tension ...

weep hole
s can be left at the base of the brick veneer to drain moisture that accumulates inside the air gap. Concrete blocks, real and cultured stones, and veneer
adobe Adobe (; ) is a building material Building material is material used for construction Construction is a general term meaning the art and science to form Physical object, objects, systems, or organizations,"Construction" def. 1.a. ...

adobe
are sometimes used in a very similar veneer fashion. Most insulated buildings that utilize concrete block, brick, adobe, stone, veneers or some combination thereof feature interior
insulation
insulation
in the form of
fiberglass Fiberglass (American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. Currently, American Englis ...
batts between wooden wall studs or in the form of rigid insulation boards covered with
plaster Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "rend ...
or
drywall Drywall (also known as plasterboard, wallboard, sheet rock, gypsum board, buster board, custard board, or gypsum panel) is a panel made of (), with or without additives, typically extruded between thick sheets of facer and backer , used in the ...

drywall
. In most climates this insulation is much more effective on the exterior of the wall, allowing the building interior to take advantage of the aforementioned thermal mass of the masonry. This technique does, however, require some sort of weather-resistant exterior surface over the insulation and, consequently, is generally more expensive.


Dry set masonry

The strength of a masonry wall is not entirely dependent on the bond between the building material and the mortar; the
friction Friction is the force In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and time, and the related en ...

friction
between the interlocking blocks of masonry is often strong enough to provide a great deal of strength on its own. The blocks sometimes have grooves or other surface features added to enhance this interlocking, and some ''dry set'' masonry structures forgo mortar altogether.


Brick

Solid
brickwork Brickwork is masonry produced by a bricklayer, using bricks and Mortar (masonry), mortar. Typically, rows of bricks called ''Course (architecture), courses'' are laid on top of one another to build up a structure such as a brick wall. Bricks m ...

brickwork
is made of two or more
wythe 250px, rightA wythe is a continuous vertical section of masonry Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. T ...
s of bricks with the units running horizontally (called ''stretcher'' bricks) bound together with bricks running
transverse Transverse may refer to: *Transverse engine, an engine in which the crankshaft is oriented side-to-side relative to the wheels of the vehicle *Transverse flute, a flute that is held horizontally *Euler force, Transverse force (or ''Euler force''), ...
to the wall (called "header" bricks). Each row of bricks is known as a course. The pattern of headers and stretchers employed gives rise to different 'bonds' such as the common bond (with every sixth course composed of headers), the English bond, and the Flemish bond (with alternating stretcher and header bricks present on every course). Bonds can differ in strength and in insulating ability. Vertically staggered bonds tend to be somewhat stronger and less prone to major cracking than a non-staggered bond.


Uniformity and rusticity

The wide selection of brick styles and types generally available in industrialized nations allow much variety in the appearance of the final product. In buildings built during the 1950s-1970s, a high degree of uniformity of brick and accuracy in masonry was typical. In the period since then this style was thought to be too sterile, so attempts were made to emulate older, rougher work. Some brick surfaces are made to look particularly rustic by including ''burnt'' bricks, which have a darker color or an irregular shape. Others may use antique salvage bricks, or new bricks may be artificially aged by applying various surface treatments, such as tumbling. The attempts at rusticity of the late 20th century have been carried forward by masons specializing in a free, artistic style, where the courses are intentionally ''not'' straight, instead weaving to form more organic impressions.


Serpentine masonry

A crinkle-crankle wall is a brick wall that follows a serpentine path, rather than a straight line. This type of wall is more resistant to toppling than a straight wall; so much so that it may be made of a single wythe of unreinforced brick and so despite its longer length may be more economical than a straight wall.


Concrete block

Blocks of cinder concrete ('' cinder blocks'' or ''breezeblocks''), ordinary concrete ('' concrete blocks''), or hollow tile are generically known as Concrete Masonry Units (CMUs). They usually are much larger than ordinary bricks and so are much faster to lay for a wall of a given size. Furthermore, cinder and concrete blocks typically have much lower
water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it acts as a ). It is vital for all known forms of , even though it provide ...

water
absorption rates than brick. They often are used as the structural core for veneered brick masonry or are used alone for the walls of factories, garages, and other industrial-style buildings where such appearance is acceptable or desirable. Such blocks often receive a
stucco Stucco or render is a construction material made of Construction aggregate, aggregates, a binder (material), binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as a decorative coating for walls and ceilings, ...
surface for decoration. Surface-bonding
cement A cement is a binder (material), binder, a substance used for construction that solidification, sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (constru ...
, which contains synthetic fibers for reinforcement, is sometimes used in this application and can impart extra strength to a block wall. Surface-bonding cement is often pre-colored and can be stained or painted thus resulting in a finished stucco-like surface. The primary structural advantage of concrete blocks in comparison to smaller clay-based bricks is that a CMU wall can be reinforced by filling the block voids with
concrete Concrete is a composite material A composite material (also called a composition material or shortened to composite, which is the common name) is a material Material is a substance Substance may refer to: * Substance (Jainism), a ter ...

concrete
with or without steel
rebar Rebar (short for reinforcing bar), known when massed as reinforcing steel or reinforcement steel, is a steel bar or mesh of steel wires used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the con ...
. Generally, certain voids are designated for filling and reinforcement, particularly at corners, wall-ends, and openings while other voids are left empty. This increases wall strength and stability more economically than filling and reinforcing all voids. Typically, structures made of CMUs will have the top course of blocks in the walls filled with concrete and tied together with steel reinforcement to form a bond beam. Bond beams are often a requirement of modern
building code A building code (also building control or building regulations) is a set of rules that specify the standards for constructed objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permission, ...
s and controls. Another type of steel reinforcement referred to as ladder-reinforcement, can also be embedded in horizontal mortar joints of concrete block walls. The introduction of steel reinforcement generally results in a CMU wall having much greater lateral and tensile strength than unreinforced walls. "Architectural masonry is the evolvement of standard concrete masonry blocks into aesthetically pleasing concrete masonry units (CMUs)." CMUs can be manufactured to provide a variety of surface appearances. They can be colored during manufacturing or stained or painted after installation. They can be split as part of the manufacturing process, giving the blocks a rough face replicating the appearance of natural stone, such as
brownstone , just south of 125th Street (2004) Brownstone is a brown Triassic The Triassic ( ) is a geologic period and system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unifi ...
. CMUs may also be scored, ribbed, sandblasted, polished, striated (raked or brushed), include decorative aggregates, be allowed to slump in a controlled fashion during curing, or include several of these techniques in their manufacture to provide a decorative appearance. "Glazed concrete masonry units are manufactured by bonding a permanent colored facing (typically composed of polyester resins, silica sand and various other chemicals) to a concrete masonry unit, providing a smooth impervious surface."
Glass block Glass brick, also known as glass block, is an architectural element made from glass. The appearance of glass blocks can vary in color, size, texture and form. Glass bricks provide visual obscuration while admitting light. The modern glass block was ...
or glass brick are blocks made from glass and provide a translucent to clear vision through the block.


Stonework

Stone blocks used in masonry can be dressed or rough, though in both examples: corners, door and window jambs, and similar areas are usually dressed. Stonemasonry utilizing dressed stones is known as
ashlar Ashlar () is finely dressed (cut, worked) stone, either an individual that has been worked until squared, or a structure built from such stones. Ashlar is the finest stone unit, generally rectangular , mentioned by as , or less frequently ...

ashlar
masonry, whereas masonry using irregularly shaped stones is known as
rubble masonry Rubble masonry is rough, uneven building stone set in mortar Mortar may refer to: * Mortar (weapon), an indirect-fire infantry weapon * Mortar (masonry), a material used to fill the gaps between blocks and bind them together * Mortar and pestle, a t ...
. Both rubble and ashlar masonry can be laid in coursed rows of even height through the careful selection or cutting of stones, but a great deal of stone masonry is uncoursed. *
Slipform stonemasonrySlipform stonemasonry is a method for making a reinforced concrete Reinforced concrete (RC), also called reinforced cement concrete (RCC), is a composite material in which concrete's relatively low ultimate tensile strength, tensile strength and d ...
produces a hybrid wall of reinforced concrete with a rubble stone face. * Natural stone veneers over CMU, cast-in-place, or tilt-up concrete walls are widely used to give the appearance of stone masonry. * Sometimes river rock of smooth oval-shaped stones is used as a veneer. This type of material is not favored for solid masonry as it requires a great amount of mortar and can lack intrinsic structural strength. * Manufactured-stone, or cultured stone, veneers are popular alternatives to natural stones. * Manufactured-stone veneers are typically made from concrete. * Natural stones from quarries around the world are sampled and recreated using molds, aggregate, and colorfast pigments. * To the casual observer there may be no visual difference between veneers of natural and manufactured stone.


Gabions

Gabion A gabion (from Italian Italian may refer to: * Anything of, from, or related to the country and nation of Italy ** Italians, an ethnic group or simply a citizen of the Italian Republic ** Italian language, a Romance language *** Regional Ita ...

Gabion
s are baskets, usually now of
zinc Zinc is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical element ...

zinc
-protected
steel Steel is an alloy An alloy is an admixture of metal A metal (from Ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appe ...

steel
(
galvanized steel Galvanization or galvanizing ( also spelled galvanisation or galvanising) is the process of applying a protective zinc Zinc is a chemical element with the Symbol (chemistry), symbol Zn and atomic number 30. Zinc is a slightly brittle metal ...
) that are filled with fractured stone of medium size. These will act as a single unit and are stacked with setbacks to form a revetment or
retaining wall Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides. Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to ( ...

retaining wall
. They have the advantage of being well drained, flexible, and resistant to flood, water flow from above, frost damage, and soil flow. Their expected useful life is only as long as the wire they are composed of and if used in severe climates (such as shore-side in a salt water environment) must be made of appropriate corrosion-resistant wire. Most modern gabions are rectangular. Earlier gabions were often cylindrical wicker baskets, open at both ends, used usually for temporary, often military, construction. Similar work can be done with finer aggregates using
cellular confinement Cellular confinement systems (CCS)—also known as geocells—are widely used in construction for erosion control Erosion control is the practice of preventing or controlling wind or water erosion In earth science, erosion is the action of ...
.


Passive fire protection (PFP)

Masonry walls have an
endothermic In thermochemistry Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or physical transformations. A reaction may release or absorb energy, and a phase change may do the same, such as in melting and bo ...
effect of its
hydrate In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds composed of atoms, m ...
s, as in chemically bound
water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it acts as a ). It is vital for all known forms of , even though it provide ...

water
, unbound moisture from the concrete block, and the poured concrete if the hollow cores inside the blocks are filled. Masonry can withstand temperatures up to 1,000ºF and it can withstand direct exposure to fire for up to 4 hours. In addition to that, concrete masonry keeps fires contained to their room of origin 93% of the time. For those reasons, concrete masonry units hold the highest
fire class A fire class is a system of categorising fire with regard to the type of material and fuel for combustion. Class letters are often assigned to the different types of fire, but these differ between territories. There are separate standards for the U ...
flame spread classification, a Class A. Masonry buildings can also be built to increase safety by reducing fire damage, such as the use of fire cuts during construction.


Mechanical modeling of masonry structures

From the point of view of material modeling, masonry is a special material of extreme mechanical properties (with a very high ratio between strength in compression and in tension), so that the applied loads do not diffuse as they do in elastic bodies, but tend to percolate along lines of high stiffness, see the figure on the right and watch
video
for more details.


See also


Masonry Associations

* * *


References


General references

* *


External links


Mason Contractors Association of America

International Masonry Institute

National Concrete Masonry Association

Masonry Institute of America

Illustrated Glossary of Stone Industry Terms
{{Authority control
Building materials Building materials Building material is material used for construction Construction is a general term meaning the art and science to form Physical object, objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford ...
Building stone